Valve automatic pressure release means

ABSTRACT

An automatic means incorporated into the structure of a system valve for releasing system pressure, the means comprising a fusible element located in the valve between the internal (high) pressure of the system and a low-pressure field such that elimination of the plug releases the system high pressure to the field low pressure. The means may additionally provide for an automatically reclosing pressure relief element such as a spring. In primary embodiments the automatic pressure release means comprises a fusible plug located in the valve stem. Pressure release is accomplished by elimination of the plug by either thermal or mechanical means, or a combination. In secondary embodiments the plug is angularly located in the valve housing.

I United States Patent [111 3,618,627

[7 Inventor William Wagner 2,295,154 9/1942 Brower 137/73 /o WatscO, Inc1300 41h Hialeah, 2,859,758 I l/l958 Jurs 137/73 Fla. 33010 3,491,783l/1970 Linsalato 137/74X [21] P 872o74 Primary Examiner-M.Cary Nelson[22] Filed Oct. 1969 Assistant Examiner Richard Gerard [45] PatentedNov. 9, 1971 Ammey Sto" & Sm

54 V LVE AUTOMATI PRESSURE REL ASE 1 MQANS C E ABSTRACT: An automaticmeans incorporated into the 1 Claim 7 Drawing 18$ structure of a svstemvalve for releasing system pressure, the means comprising a fusibleelement located in the valve U-S. CL between the internal pressure ofthe system and a low. 137/72 pressure field such that elimination of theplug releases the Int. CL ystem ressure to the low ressure The means may[50] Field of Search 137/72-74; additional), provide f an automaticallyreclosing pressure 220/89 5; 122/504- 1 504-3 reliefelement such as aspring.

in primary embodiments the automatic pressure release [56] ReferencesCited means comprises a fusible plug located in the valve stem. Pres-UNITED STATES PATENTS sure release is accomplished by elimination of theplug by 1,744,977 l/l930 Lovekin 137/72 either thermal or mechanicalmeans, or a combination. ln 1,750,335 3/1930 Taylor 220/89BX secondaryembodiments the plug is angularly located in the 1,864,380 6/l932 Te Pas137/73 valve housing.

VALVE AUTOMATIC PRESSURE RELEASE MEANS SUMMARY OF THE INVENTION Thepresent invention provides automatic means for releasing undesirablyhigh pressure in a closed system.

The present invention also provides for the incorporation of thoseautomatic means into the structure of a valve in the system.

The present invention further provides elements which automaticallyrelease high pressure by direct mechanical action of that pressure or bythermal action of ambient temperatures.

Basically, and not by way of limitation, the present inventionincorporates a fusible element into the valve stem. When the stem ishollow the element may be placed at any longitudinal positiontherewithin. Depending upon the stem contour the fusible element may bedesigned to blow out under certain internal pressures, this being inaddition to its melt out" abilities.

Additionally, a pressure-responsive spring may be utilized to providefurther pressure relief.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a cross-sectional view of afirst form of the valve automatic pressure release means of the presentinvention.

FIG. 2 is a fragmentary cross-sectional view of a modification of thefirst form of the present invention as shown in FIG. 1.

FIG. 3 is a cross-sectional view of a second form of the valve automaticpressure release means of the present invention.

FIG. 4 is a partial cross-sectional view of a modification of the secondform of the present invention as shown in FIG. 3.

FIG. 5 is a partial cross-sectional view of a second modification of thesecond form of the present invention as shown in FIG. 3.

FIG. 6 is a partial cross-sectional view of a third form of the valveautomatic pressure release means of the present invention.

FIG. 7 is a fragmentary cross-sectional view of a forth form of thevalve automatic pressure release means of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION Referring to thedrawing, a valve 10 has a main port 12 which communicates with a system(not shown) which may become pressurized. Valve 10 has a hollow stem 14the interior opening 16 in which extends fully from main port 12 throughhandle 18 to the outside to provide communication between the system andthe external field which is commonly the atmosphere. In FIG. 1 thehandle 18 and stem 14 are shown as one integral member. Handles 18a and18b, and stems 14a and 14b in FIGS. 2 and 3 respectively are shown asindependent members with the latter passing through the former.

A fusible element 20 is placed in bore 16 of stem 14 so as to plug orclose that bore. In FIG. I, bore 16 is shown enlarged at its handle endto there receive and seat a larger fusible element 20 then it wouldotherwise accommodate. The same feature is shown in FIG. 3 except thatit is the interior end portion of bore 16b which is enlarged and whichreceives and seats fusible element 20b. In FIG. 2 fusible element 20a isshown in the handle end of bore 160; there is no enlargement of thebore.

In the form of the invention shown in FIG. 3 there is a separate plunger22 which is crimped into bore 16b against fusible element 20b. Whilefusible element 201: seals bore 16b and is accordingly tightly engagedagainst the inner wall of stem 14b, plunger 22 is not so engaged and,were it not for fusible element 20b, could move longitudinally of bore16b, at least to the extent of the enlarged portion thereof.

FIGS. 4-7 show stems I4c-I4f respectively as not hollow but solid. BoresI6c-I6f respectively extend only a portion of the way into the stems atthe interior end thereof.

FIG. 4 is similar to FIG. 3 except for the showing of the nonhollowstern just indicated and except that fusible element 200 is itselfhollow or at least partially so.

FIG. 5 shows a short solid fusible element 20d in bore 16d. There is norequirement here that element 20d seal bore 16d and in fact element 20dis slidably retained in bore 16d. Bearing between fusible element 20dand plunger 22 on the one hand and the closed end of bore 16d on theother hand is a standard compression spring 24.

FIG. 6 shows spring 24 in bore Me as in FIG. 5 except that fusibleelement 202 is omitted from the bore and spring 24 bears directlyagainst plunger 22. Fusible element 20e is in a hole 26 provided for thepurpose in the main body of valve 10a. Hole 26 communicates between mainport 12 and the external field. Fusible element 20e closes and sealshole 26 and may fill hole 26 in its entirety. If the main body of valvewe is cast it is, of course, possible to place hole 26 in any locationsubject to the above and, if the mold is destructible, hole 26 couldassume any configuration. If hole 26 is drilled it can again be placedanywhere. Consideration of quantity production and industrial economydictate otherwise, however, and a die-cast valve body incorporating hole26 may preferably have the alignment and configuration shown.

That alignment and configuration facilitates use of a nondestructablepin portion of the die. Hole 26 would be located at an angle through areduced neck 28 portion of valve 10c from port 12 to the external field.The angle is such that when the longitudinal axis of hole 26 is extendedin the direction of the longitudinal axis of port 12 it does notintersect any portion of valve 102. This would permit withdrawal of thedie pin after casting.

FIG. 6 further shows hole 26 as having a larger diameter adjacent port12 than it has adjacent the external field. This would also permitdownward withdrawal of the die pin from the finished casting. It isoptional as will be indicated in the description of the operation.

FIG. 7 shows valve 10f without a plunger and with bore 16f extendedsufficiently far into stem 14f so as to pass the position of a branchport 29. A hole 27 in stem 14f extends from bore 16f through to branchport 29, hole 27 being at that location when stem 14f is in its closedposition. Fusible element 20f is in and seals hole 27.

DESCRIPTION OF OPERATION OF PREFERRED EMBODIMENTS OF THE INVENTION Thefusible elements, in all forms of the invention, block or cause theblocking of a path of communication between the relatively higherpressure of the system and the relatively lower pressure of the externalfield or branch port 29. Removal or elimination of the fusible elements,by whatever means, opens that path of communication and permitsreduction of the system pressure.

1. Thermal operation: Generally speaking, there is a direct if notlinear relation between the temperature of a closed fiuid (liquid and/orgas) system and its pressure. Thus, when undesirably high systemtemperatures are experienced, there may also be undesirably high systempressures. The present invention accordingly provides atemperature-responsive pressure relief means.

The fusible plugs, by judicious use of materials, can be manufactured tomelt at virtually any desired temperature or temperatures. Assuming thattemperature has been attained in the modes of the invention shown inFIGS. 1, 2 and 6, the fusible plug will melt out of bore 16 or 16a(FIGS. I and 2) or hole 26 (FIG. 6) and permit escape of system pressureto the external field. In the mode of FIG. 7, fusible plug 20f will meltout of hole 27 to permit escape of system pressure to the lower pressurefield of branch port 29. In the mode of FIG. 3, fusible plug 2012 willmelt out through bore 16b allowing withdrawal of plunger 22 and escapeof system pressure out branch port 29. The mode of FIG. 5 is the same inthis respect as that of FIG. 4 except that the melted material can flowinto that portion of bore I60 occupied by spring 24.

2. Mechanical operation: It is to be realized that the fusible elementwill melt only when its own temperature reaches that criticality; thetemperature of the fusible element may be only slightly related to thetemperature at a remote section of the system. Unfortunately perhapsfrom the point of view of safety a remote, even localized, temperaturerise will precipitate a system-wide pressure rise. Accordingly thepresent invention provides an automatic pressure release although thefusible element may not have reached its melting temperature by reasonfor example, of delayed heat transfer.

In the forms of the invention shown in FIGS. I, 2 and 7, high systempressure relative to field pressure will simply push the fusible elementout of its seat (bore or hole 27). The friction between the element andits seat will determine the blow out pressure and the friction is inturn determined by the seat surface condition-rough or smooth-and themethod of insertion of the fusible element. In the form of the inventionshown in FIG. 6, the shape of hole 26 will also determine thesusceptability of fusible element 20e to be blown out. In the modes ofthe invention shown in FIGS. and 6, excess system pressure will pushplunger 22 open against the selected bias of spring 24 and pennit reliefof system pressure to branch port There is thus shown a unique automaticpressure release means incorporated into the structure of a system valvefor releasing system pressure. While the foregoing is illustrative ofpreferred forms of the invention, it is clear that other forms andmodifications can be had within the broad scope of the invention and ofthe appended claims.

What is claimed is:

1. An automatic pressure release valve, comprising:

a. a valve interposed between a pressure system and a field;

b. said valve having a stem which is at least partially hollow;

c. a fusible element, said fusible element being adapted upon reachingmelting temperature to release said pressure system;

d. said fusible element being located in said valve stem hollow;

e. said fusible element being adapted to slide in said hollow and beingresponsive to pressure within said system to relieve said system at apredetermined pressure; and

f. a spring being located in said hollow and bearing against saidfusible element to resist such sliding.

1k '0 t i t

1. An automatic pressure release valve, comprising: a. a valveinterposed between a pressure system and a field; b. said valve having astem which is at least partially hollow; c. a fusible element, saidfusible element being adapted upon reaching melting temperature torelease said pressure system; d. said fusible element being located insaid valve stem hollow; e. said fusible element being adapted to slidein said hollow and being responsive to pressure within said system torelieve said system at a predetermined pressure; and f. a spring beinglocated in said hollow and bearing against said fusible element toresist such sliding.